diff --git a/Adjust/AIActivityHandler.h b/Adjust/AIActivityHandler.h
index e8a5c65c7..d71ff81d1 100644
--- a/Adjust/AIActivityHandler.h
+++ b/Adjust/AIActivityHandler.h
@@ -30,6 +30,8 @@
       withParameters:(NSDictionary *)parameters;
 
 - (void)finishedTrackingWithResponse:(AIResponseData *)response;
+- (void)setEnabled:(BOOL)enabled;
+- (BOOL)isEnabled;
 
 @end
 
diff --git a/Adjust/AIActivityHandler.m b/Adjust/AIActivityHandler.m
index c322d6294..ae02c5ed8 100644
--- a/Adjust/AIActivityHandler.m
+++ b/Adjust/AIActivityHandler.m
@@ -42,6 +42,7 @@ @interface AIActivityHandler()
 @property (nonatomic, copy) NSString *userAgent;
 @property (nonatomic, copy) NSString *clientSdk;
 @property (nonatomic, assign) BOOL trackingEnabled;
+@property (nonatomic, assign) BOOL internalEnabled;
 
 @end
 
@@ -70,6 +71,7 @@ - (id)initWithAppToken:(NSString *)yourAppToken {
     // default values
     self.environment = @"unknown";
     self.trackMacMd5 = YES;
+    self.internalEnabled = YES;
 
     dispatch_async(self.internalQueue, ^{
         [self initInternal:yourAppToken];
@@ -119,6 +121,26 @@ - (void)finishedTrackingWithResponse:(AIResponseData *)response {
     }
 }
 
+- (void)setEnabled:(BOOL)enabled {
+    self.internalEnabled = enabled;
+    if ([self checkActivityState:self.activityState]) {
+        self.activityState.enabled = enabled;
+    }
+    if (enabled) {
+        [self trackSubsessionStart];
+    } else {
+        [self trackSubsessionEnd];
+    }
+}
+
+- (BOOL)isEnabled {
+    if ([self checkActivityState:self.activityState]) {
+        return self.activityState.enabled;
+    } else {
+        return self.internalEnabled;
+    }
+}
+
 #pragma mark - internal
 - (void)initInternal:(NSString *)yourAppToken {
     if (![self checkAppTokenNotNil:yourAppToken]) return;
@@ -144,6 +166,11 @@ - (void)initInternal:(NSString *)yourAppToken {
 - (void)startInternal {
     if (![self checkAppTokenNotNil:self.appToken]) return;
 
+    if (self.activityState != nil
+        && !self.activityState.enabled) {
+        return;
+    }
+
     [self.packageHandler resumeSending];
     [self startTimer];
 
@@ -157,6 +184,7 @@ - (void)startInternal {
 
         [self transferSessionPackage];
         [self.activityState resetSessionAttributes:now];
+        self.activityState.enabled = self.internalEnabled;
         [self writeActivityState];
         [self.logger info:@"First session"];
         return;
@@ -200,7 +228,8 @@ - (void)endInternal {
 
     [self.packageHandler pauseSending];
     [self stopTimer];
-    [self updateActivityState];
+    double now = [NSDate.date timeIntervalSince1970];
+    [self updateActivityState:now];
     [self writeActivityState];
 }
 
@@ -212,12 +241,16 @@ - (void)eventInternal:(NSString *)eventToken
     if (![self checkEventTokenNotNil:eventToken]) return;
     if (![self checkEventTokenLength:eventToken]) return;
 
+    if (!self.activityState.enabled) {
+        return;
+    }
+
     AIPackageBuilder *eventBuilder = [[AIPackageBuilder alloc] init];
     eventBuilder.eventToken = eventToken;
     eventBuilder.callbackParameters = parameters;
 
     double now = [NSDate.date timeIntervalSince1970];
-    [self updateActivityState];
+    [self updateActivityState:now];
     self.activityState.createdAt = now;
     self.activityState.eventCount++;
 
@@ -247,13 +280,17 @@ - (void)revenueInternal:(double)amount
     if (![self checkEventTokenLength:eventToken]) return;
     if (![self checkTransactionId:transactionId]) return;
 
+    if (!self.activityState.enabled) {
+        return;
+    }
+
     AIPackageBuilder *revenueBuilder = [[AIPackageBuilder alloc] init];
     revenueBuilder.amountInCents = amount;
     revenueBuilder.eventToken = eventToken;
     revenueBuilder.callbackParameters = parameters;
 
     double now = [NSDate.date timeIntervalSince1970];
-    [self updateActivityState];
+    [self updateActivityState:now];
     self.activityState.createdAt = now;
     self.activityState.eventCount++;
 
@@ -275,10 +312,9 @@ - (void)revenueInternal:(double)amount
 #pragma mark - private
 
 // returns whether or not the activity state should be written
-- (BOOL)updateActivityState {
+- (BOOL)updateActivityState:(double)now {
     if (![self checkActivityState:self.activityState]) return NO;
 
-    double now = [NSDate.date timeIntervalSince1970];
     double lastInterval = now - self.activityState.lastActivity;
     if (lastInterval < 0) {
         [self.logger error:@"Time travel!"];
@@ -375,8 +411,13 @@ - (void)stopTimer {
 }
 
 - (void)timerFired {
+    if (self.activityState != nil
+        && !self.activityState.enabled) {
+        return;
+    }
     [self.packageHandler sendFirstPackage];
-    if ([self updateActivityState]) {
+    double now = [NSDate.date timeIntervalSince1970];
+    if ([self updateActivityState:now]) {
         [self writeActivityState];
     }
 }
diff --git a/Adjust/AIActivityState.h b/Adjust/AIActivityState.h
index d689af5b0..31b9637f2 100644
--- a/Adjust/AIActivityState.h
+++ b/Adjust/AIActivityState.h
@@ -13,6 +13,7 @@
 
 // persistent data
 @property (nonatomic, copy) NSString *uuid;
+@property (nonatomic, assign) BOOL enabled;
 
 // global counters
 @property (nonatomic, assign) int eventCount;
diff --git a/Adjust/AIActivityState.m b/Adjust/AIActivityState.m
index adbafc120..9cb97787c 100644
--- a/Adjust/AIActivityState.m
+++ b/Adjust/AIActivityState.m
@@ -32,6 +32,7 @@ - (id)init {
     self.createdAt       = -1;
     self.lastInterval    = -1;
     self.transactionIds  = [NSMutableArray arrayWithCapacity:kTransactionIdCount];
+    self.enabled         = YES;
 
     return self;
 }
@@ -92,6 +93,7 @@ - (id)initWithCoder:(NSCoder *)decoder {
     self.lastActivity    = [decoder decodeDoubleForKey:@"lastActivity"];
     self.uuid            = [decoder decodeObjectForKey:@"uuid"];
     self.transactionIds  = [decoder decodeObjectForKey:@"transactionIds"];
+    self.enabled         = [decoder decodeBoolForKey:@"enabled"];
 
     // create UUID for migrating devices
     if (self.uuid == nil) {
@@ -102,6 +104,10 @@ - (id)initWithCoder:(NSCoder *)decoder {
         self.transactionIds = [NSMutableArray arrayWithCapacity:kTransactionIdCount];
     }
 
+    if (![decoder containsValueForKey:@"enabled"]) {
+        self.enabled = YES;
+    }
+
     self.lastInterval = -1;
 
     return self;
@@ -117,6 +123,7 @@ - (void)encodeWithCoder:(NSCoder *)encoder {
     [encoder encodeDouble:self.lastActivity   forKey:@"lastActivity"];
     [encoder encodeObject:self.uuid           forKey:@"uuid"];
     [encoder encodeObject:self.transactionIds forKey:@"transactionIds"];
+    [encoder encodeBool:self.enabled          forKey:@"enabled"];
 }
 
 
diff --git a/Adjust/AIPackageBuilder.m b/Adjust/AIPackageBuilder.m
index 35fbe1d96..6b02d9eaf 100644
--- a/Adjust/AIPackageBuilder.m
+++ b/Adjust/AIPackageBuilder.m
@@ -9,9 +9,7 @@
 #import "AIPackageBuilder.h"
 #import "AIActivityPackage.h"
 #import "NSData+AIAdditions.h"
-
-static NSString * const kDateFormat = @"yyyy-MM-dd'T'HH:mm:ss'Z'Z";
-static NSDateFormatter * dateFormat;
+#import "AIUtil.h"
 
 #pragma mark -
 @implementation AIPackageBuilder
@@ -129,8 +127,7 @@ - (void)parameters:(NSMutableDictionary *)parameters setInt:(int)value forKey:(N
 - (void)parameters:(NSMutableDictionary *)parameters setDate:(double)value forKey:(NSString *)key {
     if (value < 0) return;
 
-    NSDate *date = [NSDate dateWithTimeIntervalSince1970:value];
-    NSString *dateString = [self.dateFormat stringFromDate:date];
+    NSString *dateString = [AIUtil dateFormat:value];
     [self parameters:parameters setString:dateString forKey:key];
 }
 
@@ -149,13 +146,5 @@ - (void)parameters:(NSMutableDictionary *)parameters setDictionary:(NSDictionary
     [self parameters:parameters setString:dictionaryString forKey:key];
 }
 
-- (NSDateFormatter *)dateFormat {
-    if (dateFormat == nil) {
-        dateFormat = [[NSDateFormatter alloc] init];
-        [dateFormat setDateFormat:kDateFormat];
-    }
-    return dateFormat;
-}
-
 @end
 
diff --git a/Adjust/AIRequestHandler.m b/Adjust/AIRequestHandler.m
index f5e4a4259..f85faca73 100644
--- a/Adjust/AIRequestHandler.m
+++ b/Adjust/AIRequestHandler.m
@@ -117,6 +117,12 @@ - (NSData *)bodyForParameters:(NSDictionary *)parameters {
         [pairs addObject:pair];
     }
 
+    double now = [NSDate.date timeIntervalSince1970];
+    NSString *dateString = [AIUtil dateFormat:now];
+    NSString *escapedDate = [dateString aiUrlEncode];
+    NSString *sentAtPair = [NSString stringWithFormat:@"%@=%@", @"sent_at", escapedDate];
+    [pairs addObject:sentAtPair];
+
     NSString *bodyString = [pairs componentsJoinedByString:@"&"];
     NSData *body = [NSData dataWithBytes:bodyString.UTF8String length:bodyString.length];
     return body;
diff --git a/Adjust/AIUtil.h b/Adjust/AIUtil.h
index a6f442ae8..5f3accd20 100644
--- a/Adjust/AIUtil.h
+++ b/Adjust/AIUtil.h
@@ -14,5 +14,6 @@
 + (NSString *)userAgent;
 
 + (void)excludeFromBackup:(NSString *)filename;
++ (NSString *)dateFormat:(double)value;
 
 @end
diff --git a/Adjust/AIUtil.m b/Adjust/AIUtil.m
index a494b317b..ac5ddd344 100644
--- a/Adjust/AIUtil.m
+++ b/Adjust/AIUtil.m
@@ -16,6 +16,9 @@
 static NSString * const kBaseUrl   = @"https://app.adjust.io";
 static NSString * const kClientSdk = @"ios3.1.0";
 
+static NSString * const kDateFormat = @"yyyy-MM-dd'T'HH:mm:ss'Z'Z";
+static NSDateFormatter * dateFormat;
+
 
 #pragma mark -
 @implementation AIUtil
@@ -110,4 +113,15 @@ + (void)excludeFromBackup:(NSString *)path {
     }
 }
 
++ (NSString *)dateFormat:(double) value {
+    if (dateFormat == nil) {
+        dateFormat = [[NSDateFormatter alloc] init];
+        [dateFormat setDateFormat:kDateFormat];
+    }
+
+    NSDate *date = [NSDate dateWithTimeIntervalSince1970:value];
+
+    return [dateFormat stringFromDate:date];
+}
+
 @end
diff --git a/Adjust/Adjust.h b/Adjust/Adjust.h
index 21d57d8c6..71db0b850 100644
--- a/Adjust/Adjust.h
+++ b/Adjust/Adjust.h
@@ -152,6 +152,18 @@ static NSString * const AIEnvironmentProduction = @"production";
  */
 + (void)trackSubsessionEnd;
 
+/**
+ * Enable or disable the adjust SDK
+ *
+ * @param enabled The flag to enable or disable the adjust SDK
+ */
++ (void)setEnabled:(BOOL)enabled;
+
+/**
+ * Check if the SDK is enabled or disabled
+ */
++ (BOOL)isEnabled;
+
 @end
 
 
diff --git a/Adjust/Adjust.m b/Adjust/Adjust.m
index 3fc29f9e3..c82d51d83 100644
--- a/Adjust/Adjust.m
+++ b/Adjust/Adjust.m
@@ -124,4 +124,12 @@ + (void)trackSubsessionEnd {
     [activityHandler trackSubsessionEnd];
 }
 
++ (void)setEnabled:(BOOL)enabled {
+    [activityHandler setEnabled:enabled];
+}
+
++ (BOOL)isEnabled {
+    return [activityHandler isEnabled];
+}
+
 @end
diff --git a/AdjustTests/AIActivityHandlerMock.m b/AdjustTests/AIActivityHandlerMock.m
index 973ec52c9..693f9b0c1 100644
--- a/AdjustTests/AIActivityHandlerMock.m
+++ b/AdjustTests/AIActivityHandlerMock.m
@@ -63,6 +63,13 @@ - (void)finishedTrackingWithResponse:(AIResponseData *)response {
     [self.loggerMock test:[prefix stringByAppendingFormat:@"finishedTrackingWithResponse response:%@", response]];
 }
 
+- (void)setEnabled:(BOOL)enabled {
+    [self.loggerMock test:[prefix stringByAppendingFormat:@"setEnabled enabled:%d", enabled]];
+}
 
+- (BOOL)isEnabled {
+    [self.loggerMock test:[prefix stringByAppendingFormat:@"isEnabled"]];
+    return YES;
+}
 
 @end
diff --git a/AdjustTests/AIActivityHandlerTests.m b/AdjustTests/AIActivityHandlerTests.m
index d754faee6..a563e7873 100644
--- a/AdjustTests/AIActivityHandlerTests.m
+++ b/AdjustTests/AIActivityHandlerTests.m
@@ -416,4 +416,80 @@ - (void)testChecks {
 
 }
 
+- (void)testDisable {
+    //  reseting to make the test order independent
+    [self reset];
+
+    //  starting from a clean slate
+    XCTAssert([AITestsUtil deleteFile:@"AdjustIoActivityState" logger:self.loggerMock], @"%@", self.loggerMock);
+
+    //  create handler to start the session
+    id<AIActivityHandler> activityHandler = [AIAdjustFactory activityHandlerWithAppToken:@"123456789012"];
+
+    // verify the default value
+    XCTAssert([activityHandler isEnabled], @"%@", self.loggerMock);
+
+    [activityHandler setEnabled:NO];
+
+    // check that the value is changed
+    XCTAssertFalse([activityHandler isEnabled], @"%@", self.loggerMock);
+
+    [activityHandler trackEvent:@"123456" withParameters:nil];
+    [activityHandler trackRevenue:0.1 transactionId:nil forEvent:nil withParameters:nil];
+    [activityHandler trackSubsessionEnd];
+    [activityHandler trackSubsessionStart];
+
+    [NSThread sleepForTimeInterval:2];
+
+    // verify the changed value after the activity handler is started
+    XCTAssertFalse([activityHandler isEnabled], @"%@", self.loggerMock);
+
+    // making sure the first session was sent
+    XCTAssert([self.loggerMock containsMessage:AILogLevelInfo beginsWith:@"First session"], @"%@", self.loggerMock);
+
+    // delete the first session package from the log
+    XCTAssert([self.loggerMock containsMessage:AILogLevelTest beginsWith:@"AIPackageHandler sendFirstPackage"], @"%@", self.loggerMock);
+
+    // making sure the timer fired did not call the package handler
+    XCTAssertFalse([self.loggerMock containsMessage:AILogLevelTest beginsWith:@"AIPackageHandler sendFirstPackage"], @"%@", self.loggerMock);
+
+    // test if the event was not triggered
+    XCTAssertFalse([self.loggerMock containsMessage:AILogLevelDebug beginsWith:@"Event 1"], @"%@", self.loggerMock);
+
+    // test if the revenue was not triggered
+    XCTAssertFalse([self.loggerMock containsMessage:AILogLevelDebug beginsWith:@"Event 1 (revenue)"], @"%@", self.loggerMock);
+
+    // verify that the application was paused
+    XCTAssert([self.loggerMock containsMessage:AILogLevelTest beginsWith:@"AIPackageHandler pauseSending"], @"%@", self.loggerMock);
+
+    // verify that it was not resumed
+    XCTAssertFalse([self.loggerMock containsMessage:AILogLevelTest beginsWith:@"AIPackageHandler resumeSending"], @"%@", self.loggerMock);
+
+    // enable again
+    [activityHandler setEnabled:YES];
+
+    [activityHandler trackEvent:@"123456" withParameters:nil];
+    [activityHandler trackRevenue:0.1 transactionId:nil forEvent:nil withParameters:nil];
+    [activityHandler trackSubsessionEnd];
+    [activityHandler trackSubsessionStart];
+
+    [NSThread sleepForTimeInterval:2];
+
+    // verify the changed value, when the activity state is started
+    XCTAssert([activityHandler isEnabled], @"%@", self.loggerMock);
+
+    // test that the event was triggered
+    XCTAssert([self.loggerMock containsMessage:AILogLevelDebug beginsWith:@"Event 1"], @"%@", self.loggerMock);
+
+    // test that the revenue was triggered
+    XCTAssert([self.loggerMock containsMessage:AILogLevelDebug beginsWith:@"Event 2 (revenue)"], @"%@", self.loggerMock);
+
+    // verify that the application was paused
+    XCTAssert([self.loggerMock containsMessage:AILogLevelTest beginsWith:@"AIPackageHandler pauseSending"], @"%@", self.loggerMock);
+
+    // verify that it was also resumed
+    XCTAssert([self.loggerMock containsMessage:AILogLevelTest beginsWith:@"AIPackageHandler resumeSending"], @"%@", self.loggerMock);
+
+}
+
 @end
diff --git a/README.md b/README.md
index 83ab85a6a..c4a4963b1 100644
--- a/README.md
+++ b/README.md
@@ -296,6 +296,20 @@ in the `didFinishLaunching` method of your Application Delegate:
 [Adjust setEventBufferingEnabled:YES];
 ```
 
+### 10. Disable tracking
+
+You can disable the adjust SDK from tracking by invoking the method `setEnabled` 
+with the enabled parameter as `NO`. This setting is remembered between sessions, but it can only
+be activated after the first session.
+
+```objc
+[Adjust setEnabled:NO];
+```
+
+You can verify if the adjust SDK is currently active with the method `isEnabled`. It is always possible
+to activate the adjust SDK by invoking `setEnabled` with the enabled parameter as `YES`.
+
+
 [adjust.io]: http://adjust.io
 [cocoapods]: http://cocoapods.org
 [dashboard]: http://adjust.io
diff --git a/VERSION b/VERSION
index fd2a01863..944880fa1 100644
--- a/VERSION
+++ b/VERSION
@@ -1 +1 @@
-3.1.0
+3.2.0